The disclosure relates to the technical field of an armature of a rotary electric machine that is mounted on, for example, a vehicle and a manufacturing method thereof.
Generally, as this type of rotary electric machine, known is an electric motor. The electric motor has a yoke where magnetic poles are formed by a plurality of pairs of permanent magnets provided on the inner circumferential surface and an armature. A plurality of slots are formed in the armature extending in an axial direction around the circumferential direction on the outer periphery of a core. A plurality of coils, each coil formed by winding wire wound in the slots with a predetermined interval, conduct an electric current to adjoining commutator segments. When a high torque, as well as a reduction in size, are demanded in such an electric motor, the demand has been satisfied by providing the electric motor with multiple poles by using a plurality of pairs of permanent magnets and increasing the number of commutator segments and slots. However, in such an electric motor, it has been known that, when the commutator segments around which and to which coil ends are hung and connected and coil winding positions are lap-wound in a state where these are almost opposed in the axial direction, magnetic imbalance occurs to cause whirling based on a torque ripple and the like.
As a remedy therefore, it has been promoted to form coils by winding a winding wire that conducts an electric current to arbitrary commutator segments around the preset arbitrary slots and the slots facing the arbitrary slots in the radial direction in a state of series connection and to thereby improve magnetic balance (see Japanese Published Unexamined Patent Application No. 2002-305861).